1. Field of the Invention
The present invention relates to an internet server and method of controlling the internet server.
2. Related Art
The internet has developed rapidly over the past few years and has resulted in increased traffic over telecommunications networks. One particular factor which has made the internet more `user friendly` is the development of the World Wide Web (WWW) service which uses the HyperText Transfer Protocol (HTTP) specification. In order to utilise the WWW service, the user will utilize what is termed a browser, which is software which can interpret hypertext mark-up language (HTML) files which are sent from an internet WWW server to create a web page on the screen of the user's computer. FIG. 1 illustrates a typical internet configuration wherein a user is connected to the internet and uses the WWW service using a browser 1.
In order to initiate the generation of a web page, i.e. to connect to a WWW server such as first server 2, which has a low storage and processor capacity and is linked to the internet via a low bandwidth connection, a request for an HTML file must be transmitted by the browser 1 to the WWW server 2. In order to identify and locate a file in a server from amongst the servers connected to the internet, the file is identified by a universal resource locator (URL). The URL is structured to identify the protocol (which in this case is HTTP), the internet server, the directory of the file in the internet server and the file name. Thus the URL structure is:
http://internet server/directory/file name PA1 receiving a file request; PA1 determining if the file request includes an identification signal identifying the originating file from which said request originated; PA1 comparing any said identification signal with one or more predetermined identification signals; and PA1 deciding what file if any is to be transmitted to said user in dependence upon said determining and comparing steps, and if in the deciding step it is decided that a file is to be transmitted, transmitting said file from said server to said user. PA1 receiver means for receiving a file request; PA1 determining means for determining if the file requested includes an identification signal identifying the originating file from which said request originated; PA1 comparison means for comparing any said identification signal with one or more predetermined identification signals; PA1 decision means responsive to said comparison means for deciding what file if any is to be transmitted to said user; and PA1 an output for outputting a file for tranmission to said user if said decision means decides that said file is to be transmitted.
When a URL is selected by a user, the browser 1 transmits a file request over the internet to the first server 2 which has the address identified in the URL of the file requested in a HTML file. The first server 2 will then send the HTML file to the browser 1. The browser 1 then interprets the HTML file in order to generate a web page.
The HTML specification allows for text to be displayed and for hypertext links to be included in the web page. Also, the HTML protocol allows graphics or image files to be included in the web page displayed by the browser 1. The HTML protocol thus allows for image files which are to be displayed by the browser 1 to be identified by their URL. When the browser 1 interprets the HTML file returned from the first server 2, if the HTML file includes image URL's, the browser 1 will seek to retrieve the image files using the URL of the image file. Thus, the image or graphics files are retrieved separately to the HTML file and when a web page is displayed by the browser 1, the graphics included in the web page can take longer to display as the file is retrieved after the HTML file.
Since the image file required to complete the web page is identified by a URL there is no requirement for the image file to be located at the first server 2 which supplied the HTML file. Because image or graphics files can be quite large files, the transmission of such files over the internet can take a significant period of time when transmitted over a route with a relatively limited data rate. The ability of a browser 1 to locate and retrieve image or graphics files which are referred to in the web page and which are located anywhere in the internet, allows an internet server providing web pages to utilize this to avoid having to store image or graphics files required to complete the web page created by the HTML file. Further, such a first server can be connected to the internet over a low bandwidth connection without risking a bottleneck. A second server 3 in the internet which has a high storage and processor capacity which hosts the graphics or image files referred to in the web page is thus the subject of bandwidth-consuming graphic file requests from the browser. Such a second server 3 can for instance be an internet server which is connected to the internet over a high bandwidth connection.
FIG. 2 illustrates in more detail a method of operation when such a system of referring to graphics pages at another server is used.
When the browser 1 is initialised, a URL for an HTML file is input or selected by a user in step S1. The browser then requests connection to the server identified in the URL in step S2 and in step S3 the browser connects to the server. The browser then sends a request for the HTML file in step S4 and in step S5 the server sends the HTML file which is then interpreted by the browser in step S6. The web page generated by the interpretation of the HTML file is then displayed in step S7. At this point the web page will include only the text and the hypertext links. In step S8 the browser determines whether the HTML file refers to any image URLs. If not, the browser will await to determine whether any URL is selected for instance using the hypertext links in step S9. If a new URL is selected in step S9 the browser returns to step S2 to request a connection to the same or another server. If no new URL is selected the browser will end requesting files in step S10. If in step S8 it is determined that the HTML file refers to image or graphics URLs, in step S11 the browser requests connection to the second server 3 (or other servers) identified in the URL of the image file. In step S12 the browser connects to the second server 3 (or other servers) and in step S13 the browser 1 sends a request for the image file. The second server 3 then sends the requested image file in step S14 and in step S15 the browser displays the image file within the web page. Step S8 and steps Sl1 to S15 will be carried out simultaneously to retrieve as many image files as are required, i.e. referred to in the HTML file, in order to complete the web page.
It will be seen from the above that the ability of the HTML protocol to allow an HTML file to refer to image files at any server connected to the internet using the URL, allows the first server 2 to make use of image or graphics files in the second server 3 thus reducing the cost of storage at the first server 2. The first server requires less processing time and less bandwidth to deliver the complete web page to the browser 1. Also, the development of web pages by the operator of the first server 2 is easier and cheaper, since there is no need for the operator to create custom artwork. They are simply able to use images available on other servers.